What are the possible genotypes of parents in fragile x syndrome?

Answer 1

A/X X/A NIKKI SMITH **** Less than 1% of Fragile X Syndrome cases are a result of deletion, neither parent is a carrier. If a father is the carrier/full mutation, XY, he will pass the mutated gene to all of his daughters, all of his daughters will be carriers. If the mother is the carrier/full mutation, xX, with each pregnancy she has the possiblity of passing on fragile X as a pre-mutation (carriers) or full-Mutation to every child (male/female).

Answer 2

Down's syndrome by definition is an over representation of chromosome 21. The most common type is trisomy 21, in which case the genotype of the person with Down's syndrome is 3 copies of chromosome 21. This is denoted as:

47, XX, +21 - if a female

47, XY, +21 - if a male

Another type is when the extra piece of chromosome 21 attaches to somewhere else, in which case the genotype will still be 46, but the notation will show where it has attached to. An example would be:

45, XX, t(12:21) - if a female where it stuck to chromosome 12

45, XY, t(17:21) - if a male where it stuck to chromosome 17

People with Down's syndrome are almost invariable unable to have children of their own.

The genetics of the parents of the child with Down's syndrome is normal.

Answer 3

Klinefelter's, is a mutation, so a person with such disease, would have normal parents (XY, XX). Klinefelter's is the result of nondisjunction of the sex chromosomes, causing trisomy of the sex chromosome, (XXY) not because of a mutation in the somatic cells of the parents, but instead of the mutation in the gametes (sex cells) of the parent.

Answer 4

1. i think it is

xy

xx xx xy

xx xy